Mechanisms of inulin addition affecting the properties of chicken myofibrillar protein gel

Emulsion co-stabilized with high methoxyl pectin and myofibrillar protein: Used to enhance the application in emulsified gel

This study evaluates the effects of high methoxyl pectin on the emulsion and gel properties of silver carp myofibrillar protein. An optimal concentration of pectin (3 mg/mL) enhances protein adsorption at the oil-water interface, forming a thermally induced oil-in-water emulsion gel with a denser and more robust fibrous network. The resulting gel exhibits a 3.8-fold increase in hardness and a 1.35-fold increase in water-holding capacity compared to the control. However, higher pectin concentrations (4-5 mg/mL) degrade emulsion-gel quality. By adjusting the ratio of myofibrillar protein to pectin, the emulsion's texture can transition from a fluid to a semi-solid state at room temperature, and the gel quality under heat treatment can be controlled. These findings offer a pathway to broaden the design and application of myofibrillar protein emulsions in multifunctional food products.

Effect of β-glucan on the gelling properties of unwashed silver carp surimi gel: Insights into molecular interactions between different sources of β-glucan and myofibrillar protein

Gel property is one of the most important abilities to surimi products. In this research, the β-glucan from yeast and oat were applied in enhancing the gel properties of unwashed surimi gel. The texture profile analysis (TPA), storage modulus (G'), loss modulus (G") of unwashed surimi gel, and β-glucan linking with myofibrillar protein were investigated, at the addition of 0 %-1.5 % β-glucan. The β-glucan from yeast and oat could induce more unfolding and promoted cross-linking of myofibrillar protein, improving the hardness and gel strength of unwashed surimi gel. At the 1.0 % addition of yeast β-glucan (YG) or oat β-glucan (OG), the gel strength of unwashed surimi gel increased by 434.30 g·mm and 314.39 g·mm, respectively, compared with the control. In addition, YG with a branched-chain structure was more likely to crosslink with myofibrillar protein (MHC) through hydrogen bond, and YG-MHC CDOCKER energy lower than OG-MHC, proved by molecular docking analysis. The grafting degree and intermolecular interactions in the YG treated surimi gel are stronger than those in the OG one, enhancing the physical properties and WHC of unwashed surimi gel. However, as the added amount β-glucan increased 1.5 %, the pores in the network became excessively expansive, the continuous structure of the myofibrillar protein was gradually destroyed, leading to the decreasing gel properties and rheological properties. In conclusion, 1.0 % YG treatment can effectively improve the gel properties of unwashed surimi gel, providing a practical method for the processing of myofibrillar protein based gel products.

Assessing how the partial substitution of phosphate by modified chickpea protein affects the technofunctional, rheological, and structural characteristics of pork meat emulsions

The effects of high-pressure homogenization (HPH, 80 MPa, two cycles) and/or heat-treatment (80 °C, 30 min) modified chickpea protein (CP) on water- and fat-binding capacities, texture, color, and flavor attributes of reduced-phosphate (0.2 % sodium tripolyphosphate, STPP, w/w) pork meat emulsions (RPMEs) were evaluated. The results showed that either HPH or heat-treatment modified CP exhibited a considerable improvement in emulsion stability, textural attributes (hardness, cohesiveness, and chewiness), and b⁎ values (P < 0.05), promoted the formation of inorganic and organic sulfide compounds, and enhanced the umami, richness, and saltiness of RPMEs. Moreover, HPH + heat-treatment dual-modified CP showed superior enhancement effects on most technofunctional properties, thereby imparting the meat emulsion with quality characteristics comparable with high-phosphate control (0.4 % STPP, w/w). Hierarchical cluster analysis and partial least squares regression analysis suggested that the changes in technofunctional traits of RPMEs containing modified CP could be associated with rheological and structural modifications in meat emulsions. Theses alterations included enhanced viscoelasticity, elevated stabilization of internal water, reinforced aliphatic-residue hydrophobic interactions, strengthened intermolecular hydrogen and disulfide bonding, the uncoiling of α-helices concurrent with the formation of β-sheets and random coils, and an increased fractal dimension and decreased porosity of the gel networks. Therefore, HPH combined with heat-treatment modified CP is an intriguing phosphate substitute for developing reduced-phosphate meat products.

Exploring the gelation potentials of chicken heart batter: From by-product to product

Chicken heart is the by-product of great amount in poultry industry owing to concentrated slaughter development, however, whose potential in food application is unclear. The gelation of chicken heart has great difficulties due to the muscle structure and protein structure of the heart. Therefore, different levels of sodium alginate (SA) were added into chicken heart batter (CHB) to investigate the gelation strategies. The results showed that the cooking loss of chicken heart gel (CHG) decreased by increasing SA level (0.12 %-0.48 %)，along with improved hardness, gumminess and chewiness. The G' and G" of CHB increased along with the SA addition, which mainly relates to hydrophobic interactions and disulfide bonds, followed by ionic bond and hydrogen bond. SA induced increased percentage of immobilized water and bound water. Moreover, the protein-SA interpenetrating network became denser and more uniform along with increased SA in CLSM and SEM images until CHG of 0.48 % SA. To the best of our knowledge, this is the first time that chicken heart is processed into gelation food, which endeavors to promote feed to food by a sustainable proposal.

How chloride salt mixtures affect the final gel properties of low-sodium myofibrillar protein: Underlining the perspective of gelation process

This study aimed to investigate the performance differences of low-sodium myofibrillar protein (MP) gels substituted by different chloride salt mixtures from the perspective of gelation process. The results revealed that low-sodium MP substituted by KCl/CaCl2 exhibited higher turbidity and particle size at 40 % substitution, and formed protein aggregates earlier at 53 °C. During the gelation process, KCl/CaCl2 increased the extent of cross-linking as the substitution level increased from 10 % to 40 %, which was prone to forming final gels with poor palatability. Microstructural and binarization results visually indicated that an irregular reticular structure composed of partial clusters formed when the temperature heated over 53 °C, and the cross-linked cluster blocks further shrunk from 53 °C to 73 °C. Rheological amplitude sweeps revealed that KCl/CaCl2-substitued MP displayed a faster fracture of the ductile structure, and this influenced the distribution of cluster blocks inside the network. The introduction of salt mixtures altered protein conformation, and more unordered structures were found in low-sodium MP containing CaCl2, rather than MP containing MgCl2. Additionally, Ca2+ ions increased the thermo-denatured temperature of MP, and extended the relaxation time of bound water at 53 °C, and Mg2+ ions slowed down the degree of liquid loss at 53 °C. As a result, the low-sodium MP containing CaCl2 exhibited a lower expansion of protein structure accompanied by the involvement of less proteins in gel formation and more liquid loss in the final gel.

Influence of Pleurotus eryngii Protein on Myofibrillar Protein Gelation and Application in Chicken Mince Products

Pleurotus eryngii is rich in essential proteins, and is recognized for its medicinal and nutritional attributes. This study investigated the effects of P. eryngii protein (PEP) incorporation (0-7%) on the gel characteristics of chicken myofibrillar protein (MP) to develop a chicken mince product, providing theoretical supports for the development of functional restructured meat products. PEP incorporation improved the rheological and textual properties of the composite gels, enhancing hydrophobic interaction and disulfide bond formation, and thereby strengthening the gel characteristics. The optimal chicken mince quality was achieved with the incorporation of 3% P. eryngii powder. These findings highlight that PEP contributes to the MP gel functionality by modifying the gel structure and strengthening the molecular bonds, laying a foundation for applying PEP in food processing.

Influence of dietary resveratrol supplementation on integrity and colloidal characteristics of Myofibrillar proteins in broiler chicken breast meat

Abstracts This study was designed to elucidate the impact of dietary resveratrol (RES) supplementation on the free radical activity within the breast muscle of broiler chickens and to assess its effects on the structural and colloidal attributes of myofibrillar proteins (MPs). A total of 180 1-day-old male AA broiler chickens was divided to 2 groups (a CON group fed a control diet and a RES group fed the control diet supplemented with 400 mg/kg RES), each with 6 replicates and 15 chickens per replicate. The feeding test lasted for 6 weeks. The findings indicate that RES, recognized for its potent antioxidant properties, markedly diminished free radical activity, thereby curtailing the oxidative degradation of MPs and augmenting the integrity of their conformational structure. The intricate MP conformation is pivotal in dictating the functional attributes of the protein colloid. RES supplementation was observed to diminish the mobility of water molecules, thereby enhancing the stability of the colloidal system and improving the water-holding capacity and the visual appeal in terms of whiteness of colloid. Concurrently, the stabilization of the protein structure facilitated an increase in the intermolecular cohesive forces within the colloid, resulting in a denser and more stable microstructure, which significantly bolstered the mechanical strength of the colloid. In summary, the incorporation of RES as a dietary supplement in poultry feed presents a promising strategy to fortify the stabilization of proteins in chicken breast meat, offering a valuable alternative for the production of high-quality poultry meat products.

The dual role of mannosylerythritol lipid-A: Improving gelling property and exerting antibacterial activity in chicken and beef gel

Gel meat products are important in the meat market. To develop high-quality meat gel products, mannosylerythritol lipid-A (MEL-A) was added to chicken and beef gels, and their physicochemical and biological properties of the composite gel formed by heating were determined in this study. The results of texture analysis showed that MEL-A could significantly improve the hardness, gumminess and chewiness of meat gels and reduce water loss (P < 0.05). In addition, rheological and differential scanning calorimetry (DSC) analysis showed that MEL-A not only improved the rheological properties of meat gel, but also improved its thermal stability. The results of dynamic rheological analysis also showed that MEL-A improved the gel strength of meat gel, and the gel strength of chicken was the highest after adding 1.5 % MEL-A while the gel strength of beef was the highest after adding 2 % MEL-A. The image of scanning electron microscopy (SEM) and protein molecular weight distribution measurement indicated that MEL-A induced protein aggregation, resulting in fewer pores in the meat gels and a more compact network structure. These results suggest that different meat gels show good gel properties, so MEL-A has a lot of potential for gel product development.

Mechanism of brittleness deterioration of pork meatballs induced by freeze-thaw cycles based on ice crystals and molecular conformation

This study investigated the mechanism behind the gradual disappearance of the unique brittle texture of pork meatballs during multiple freeze-thaw (FT) cycles. The results showed that meatball brittleness decreased with increasing numbers of FT cycles. However, unexpected partial recovery occurred at FT3 and FT5, with the water holding capacity decreasing (74 %/81 %), and the fractal dimension (1.4502/1.6592) and size (76.9 µm2/414.7 µm2) of ice crystals increasing. During the FT cycles, tiny ice crystals and salt-ion crystals remaining from the previous FT process gradually increased in size under the influence of the Ostwald effect. By FT3, the ice crystals had transformed from relatively regular spheres to irregular dendritic structures, which pierced and disrupted the three-dimensional gel network, triggering new protein cross-linking driven by ionic bonding and hydrophobic interactions. By FT5, after multiple degradations and re-aggregations, the proteins formed heterogeneous aggregates with heavy chains of actin and myosin as the main components, bound by hydrogen and disulfide bonds, which was a partial reversion to the degree of cross-linking of the gelatinized network structure of the meatballs. This study revealed the effects of changes in the ice crystal state, protein aggregation morphology, and molecular conformation on the brittleness of meatballs during FT cycles, providing a theoretical foundation for developing freezing protection technologies.

Effect of chitosan on thermal gelling properties of pork myofibrillar protein and its mechanism

BACKGROUND

Previous studies have demonstrated that the addition of chitosan can improve the quality and functional properties of meat products. However, the underlying mechanism remains unclear. In this study, the effect and mechanism of the addition of chitosan on the gel properties of myofibrillar protein (MP) were investigated.

RESULTS

The results indicated that the gel strength and the water-holding capacity of MP-chitosan gel increased significantly when chitosan was added at 2.5-10 mg mL-1. Myofibrillar protein samples with 10 mg mL-1 added chitosan exhibited the highest elasticity and viscosity during gel formation and strengthening. The addition of chitosan also caused a modification in both the secondary and tertiary structure of MP, resulting in an enhanced exposure of hydrophobic and sulfhydryl groups in comparison with the control. Chitosan inhibited the conversion of immobilized water into free water and the formation of water channels during the thermal gelation process of MP. The denaturation enthalpy (ΔH) of myosin decreased as the concentration of chitosan exceeded 5 mg mL-1. The microstructure showed that the incorporation of chitosan (5-10 mg mL-1) facilitated the formation of compact and well organized MP gel networks.

CONCLUSION

The addition of chitosan can enhance the functional properties of meat protein and facilitate heat-induced gelation, making it a promising ingredient for improving the quality of processed meat products. © 2024 Society of Chemical Industry.

Effect of chickpea protein modified with combined heating and high-pressure homogenization on enhancing the gelation of reduced phosphate myofibrillar protein

The effects of chickpea protein (CP) modified by heating and/or high-pressure homogenization (HPH) on the gelling properties of myofibrillar protein under reduced phosphate conditions (5 mM sodium triphosphate, STPP) were investigated. The results showed that heating and HPH dual-modified CP could decrease the cooking loss by 29.57 %, elevate the water holding capacity by 17.08 %, and increase the gel strength by 126.88 %, which conferred myofibrillar protein with gelation performance comparable with, or even surpassing, that of the high-phosphate (10 mM STPP) control. This gelation behavior improvement could be attributed to enhanced myosin tail-tail interactions, decreased myosin thermal stability, elevated trans-gauche-trans disulfide conformation, strengthened hydrophobic interactions and hydrogen bonding, the uncoiling of α-helical structures, the formation of well-networked myofibrillar protein gel, and the disulfide linkages between the myosin heavy chain, actin, and CP subunits. Therefore, the dual-modified CP could be a promising phosphate alternative to develop healthier meat products.

Impacts of kappa-selenocarrageenan on the muscle quality of pork: Novel insights into myofibrillar protein and lipid oxidation

Excessive oxidation of protein and lipids in pork leads to quality degradation and loss of nutrients. Kappa-selenocarrageenan (Se-K) can not only be used as a selenium enhancer but also as an antioxidant. To explore potential antioxidants that could be applied to pork, the effect of Se-K on myofibrillar protein (MP) and lipid oxidation was investigated. The results demonstrated that Se-K could scavenge hydroxyl radicals, DPPH radicals, and ABTS radicals. It was found that Se-K inhibited the formation of carbonyls and decreased the loss of sulfhydryl groups of MP. Se-K also inhibited cross-linking, aggregation, unfolding, and structural transformation of MP and repressed the increase in surface hydrophobicity. Additionally, Se-K enhanced the emulsibility, textural properties, and water-holding capacity of MP. We also found that Se-K delayed the increase in acid value, peroxide value, and thiobarbituric acid reactive substances value. Furthermore, Se-K inhibited the degradation of unsaturated fatty acids, especially linoleic acid. Overall, Se-K was effective in inhibiting MP and lipid oxidation and could be a potential antioxidant for pork.

Structural and gel property changes in chicken myofibrillar protein induced by argon cold plasma-activated water: With a molecular docking perspective

This study investigated the effects of plasma-activated water (PAW) generated with argon at discharge times of 0, 4, 8, 12, and 16 min on the gel properties and structures of chicken myofibrillar protein (MP). Under treatments of 8, 12, and 16 min, both the gel strength and water retention capacity of MP significantly improved, with the gel strength (0.53 N) peaking at 16 min and the lowest cooking loss（30.38 %）. As the treatment time increased from 0 to 16 min, the storage modulus also gradually increased. Results from low-field nuclear magnetic resonance indicated a slowing of water proton mobility, with the proportion of bound water rising from 0.26 % (0 min) to 0.52 % at 16 min. Fourier transform infrared spectroscopy, endogenous fluorescence spectroscopy and scanning electron microscopy confirmed PAW's alteration of MP's secondary and tertiary structures and gel microstructure. Additionally, this study explored the influence of argon PAW's primary active species on MP from a molecular docking perspective·H2O2 could form hydrogen bonds with MP, while O3 and NO2‾could interact via both hydrogen bonds and electrostatic interactions. Thus, PAW can alter protein structure and enhance MP's functional properties, providing insights for applying cold plasma in processing chicken gel products.

Structural and functional impacts of glycosylation-induced modifications in rabbit myofibrillar proteins

Rabbit meat, recognized for its nutritional value, is gaining global attention. However, the inferior functional properties of rabbit myofibrillar proteins lead to quality degradation during the production process. Glycosylation represents an effective method for enhancing protein functionality. This study investigated the glycosylation modification of rabbit myofibrillar proteins. The results demonstrated that solubility of glucose-glycosylated products increased by 34 %, while the reduction capacity improved from 0.15 mg/mL to 1.6 mg/mL. The·OH free radical scavenging ability increased from 63.94 % to 94.21 %. β-Glucan-glycosylated products exhibited the highest thermal stability, and their DPPH free radical scavenging rate increased from 19.68 % to 76.21 %. Glycosylation also induced changes in protein conformation, characterized by a 10-30 °C increase in thermal denaturation peak temperature, gradual attenuation of endogenous fluorescence intensity, gradual enhancement of λmax redshift, and a 30-40 % decrease in surface hydrophobicity. Molecular docking simulations revealed that the primary interactions between glucose, lactose, and β-Glucan with myofibrillar proteins involve hydrogen bonds and van der Waals forces. In conclusion, glycosylation can effectively improve the functional properties of proteins, contributing to the development and production of high-quality, stable, and nutritious rabbit meat products.

Limited enzymatically hydrolyzed pea protein-inulin interactions in gel systems

Gelation of protein-polysaccharide mixtures can help create a variety of distinctive gel systems as compared to single polysaccharide or protein gels. The properties of these functional gels are heavily reliant upon the nature of protein-polysaccharides interactions, their gelling compatibility, and mechanism. Pea protein isolate dispersions (7.5%) were subjected to limited enzymatic hydrolysis using the enzyme Alcalase® at three hydrolysis times (0, 3, and 6 min). Inulin was added according to three ratios (0, 1:4, and 2:4) with pea protein. Viscoelastic properties of the gels formed were measured using amplitude sweep and frequency sweep. Storage modulus (G') measurements from the amplitude sweep indicated that samples hydrolyzed for 3 min with 1:4 ratio of inulin to pea protein had maximum gel strength, exhibiting G' values of ∼307 Pa. G' values for samples hydrolyzed for 0 and 6 min with different inulin ratios averaged ∼13 and ∼144 Pa, respectively. Confocal laser scanning microscopy showed that gels developed by samples hydrolyzed for 3 min showed a dense network as compared to an open network in gels formed by samples hydrolyzed for 6 min, whereas large random aggregates were observed in gels formed by samples hydrolyzed for 0 min. The study confirmed that inulin promotes noncovalent bond formation in samples hydrolyzed for 3 min with a 1:4 inulin ratio, shown by an ∼18% increased protein solubility in urea. Additionally, collaboration between noncovalent bonds and disulfide linkages stabilized the gel structure, as indicated by further increase in solubility in combination of urea and Dithiothreitol. PRACTICAL APPLICATION: Plant proteins are gaining attention as alternatives to animal proteins. However, they have inferior functionality, which affects their applicability in food products. This investigation aimed to evaluate enzymatic hydrolysis to enhance the structural and functional properties of pea proteins, thus increasing their applicability in the food industry. Inulin is an oligosaccharide and soluble fiber, which promotes gut health. Thus, gels combining hydrolyzed pea protein and inulin can serve as a model mixed food system of interest to both the industry and consumers.

Gelatinous quality and quantitative proteomic analyses of snakehead (Channa argus) surimi treated by atmospheric cold plasma

In this study, the comprehensive quality characteristics and proteome changes of snakehead (Channa argus) surimi gel under different atmospheric cold plasma (ACP) treatment times were systematically analyzed and compared. The results showed that the ubiquitin-associated proteins and heat shock proteins were activated after ACP treatment for 90 s (ACP90), thus inducing rearrangement of surimi structural proteins. Meanwhile, the increased hydrophobic interactions and disulfide bonds might strengthen the interactions among the myofibrillar protein, keratin, and type-I collagen, which led to the formation of a dense gel network. Moreover, the high nodality between actin and myosin promoted the regulation of muscle contraction by changing the spatial obstruction of their binding sites. These beneficial effects obviously contributed to the superior water-holding capacity (76.13%), gel strength (285.6 g·cm) and viscoelasticity of snakehead surimi in the ACP90 group. These results would provide some useful information for the in-depth and efficient processing of surimi products.

Abelmoschus manihot gum improves the water retention capacity of low-salt myofibrillar protein gels: Perspective on aggregation behaviour and conformational changes during heating

This study aimed to investigate the effect of Abelmoschus manihot gum (AMG) on the water retention capacity of low-salt myofibrillar protein (MP) gel by analysing its aggregation behaviour and conformational changes during heating (30-80 °C). The results revealed that AMG significantly increased the water holding capacity and facilitated the formation of a more uniform gel network structure in low-salt MP gel (P < 0.05). During the heat-induced gelation process, the solubility of low-salt MP significantly decreased, whereas its turbidity evidently increased as the level of added AMG increased (P < 0.05). Furthermore, the dynamic rheological behaviours indicated that low-salt MP-AMG gels underwent early denaturation and unfolded at 58 °C, finally forming an irreversible three-dimensional network at 80 °C. Moreover, adding AMG promoted α-helix-to-β-sheet transition in low-salt MP and decreased its fluorescence intensity during the heating process. Hydrophobic interactions and disulfide bonds were the two dominant forces governing the formation and maintenance of low-salt MP gel. The present study provides theoretical guidance for the production of novel low-salt healthy meat products.

Development and characterization of tilapia skin collagen-inulin oleogel as the potential fat substitute in beef patty formulations

The effects of inulin addition, olive oil content, and ultrasonic treatment on the rheological, texture, and structural properties of collagen-based oleogels were investigated in this study. Furthermore, the fat substitution ability of the oleogel in low-fat beef patties was evaluated. Initially, a uniform and dense network cross-linked structure was found when the ratio of collagen to inulin complex was 1:5. The oleogel sample exhibited good stability and oil binding ability with an additional amount of 50 % olive oil. Ultrasonic treatment improved the stability of the oleogel structure in all samples. Additionally, the addition of inulin reduced cooking loss in beef patties. Beef patties prepared at a 50 % fat substitution level showed physical properties that were the least different from those of pure adipose tissue (control group), which could significantly reduce the content of saturated fatty acids and improve the storage stability of beef patties. This study provided guidance for the application of collagen-inulin oleogel in food processing.

Insight into the effects of ultrasound-assisted intermittent tumbling on the gelation properties of myofibrillar proteins: Conformational modifications, intermolecular interactions, rheological properties and microstructure

The aim of the present study was to evaluate the effects of ultrasound-assisted intermittent tumbling (UT) at 300 W, 20 kHz and 40 min on the conformation, intermolecular interactions and aggregation of myofibrillar proteins (MPs) and its induced gelation properties at various tumbling times (4 and 6 h). Raman results showed that all tumbling treatments led the helical structure of MPs to unfold. In comparison to the single intermittent tumbling treatment (ST), UT treatment exerted more pronounced effects on strengthening the intermolecular hydrogen bonds and facilitating the formation of an ordered β-sheet structure. When the tumbling time was the same, UT treatment caused higher surface hydrophobicity, fluorescence intensity and disulfide bond content in the MPs, inducing the occurrence of hydrophobic interaction and disulfide cross-linking between MPs molecules, thus forming the MPs aggregates. Additionally, results from the solubility, particle size, atomic force microscopy and SDS-PAGE further indicated that, relative to the ST treatment, UT treatment was more potent in promoting the polymerization of myosin heavy chain. The MPs aggregates in the UT group were more uniform than those in the ST group. During the gelation process, the pre-formed MPs aggregates in the UT treatment increased the thermal stability of myosin, rendering it more resistant to heat-induced unfolding of the myosin rod region. Furthermore, they improved the protein tail-tail interaction, resulting in the formation of a well-structured gel network with higher gel strength and cooking yield compared to the ST treatment.

Effect of chitosan oligosaccharides with different molecular weight in alleviating textural deterioration of chicken myofibrillar protein gel with high-temperature treatment

The molecular weight (MW) of oligosaccharides on gel properties of myofibrillar protein (MP) at high temperature remains unclear. In this study, it was found that chitosan oligosaccharides (CO) with different MW all significantly alleviated the textural deterioration of MP gel with high-temperature treatment. Moreover, MP-CO gel with the largest MW had the highest breaking force and the lowest cooking loss. Low-field NMR results further indicated that MP-CO gel with larger MW of CO had gradually increased relaxation rate, thus binding water more tightly. Rheological and microrheological tests suggested the addition of CO with larger MW resulted in much tighter gel network. These results indicated that CO with larger MW improved the quality of MP gel more effectively, which was because CO with larger MW inhibited aggregation of MP to a larger extent, resulting in smaller MP aggregates. Then MP-CO gel with much denser and more homogeneous structure was formed. Besides, MP-CO gel with larger MW of CO had higher content of β-sheet, resulting in MP gel with more ordered structure and better gel quality. Therefore, this study provided theoretical guidance for choosing the appropriate CO in improving texture of high temperature meat products.

Effect of ultrasound combined with highland barley dietary fiber on gel properties of reduced-salt chicken breast myofibrillar protein

This study aimed to investigate the effect of ultrasound combined with highland barley dietary fiber (HBDF) on the quality of reduced-salt chicken breast myofibrillar protein (MP) gel. The molecular forces maintaining gel structure, the gelling formation process, and gel microstructure of different groups, two control groups (2% sodium chloride [NaCl] group, 1% NaCl group), and four treatment groups (0.3% HBDF+U5, 0.3% HBDF+U10, 0.5% HBDF+U5, and 0.5% HBDF+U10) were examined. Results indicated significant improvements (p < 0.05) in gel properties such as water-holding capacity, textural characteristics, and color of the MP gel of the four treatment groups compared to Control 2 (1% NaCl) group. Furthermore, the second structural alterations were characterized by increase β-sheet, β-turn, and random coil structure contents in treatment groups, especially in 0.3% HBDF+U5 and 0.5% HBDF+U5 groups; in addition, the exposure of more hydrophobic groups and the formation of disulfide bonds and hydrogen bonds were promoted in treatment groups, thus enhancing protein aggregation and gel quality. Finally, compared to Control 2 (1% NaCl) group, more compact and uniform gel network structures and pores inside the composite gels were observed in treatment groups. In conclusion, the findings demonstrated that the application of ultrasound in combination with HBDF improved the gelling characteristics of reduced-salt chicken breast MP gel, especially 0.3% HBDF+U5 and 0.5% HBDF+U5 groups.

Influence of flaxseed-derived diglyceride-based high internal phase Pickering emulsions on the rheological and physicochemical properties of myofibrillar protein gels

The study aimed to investigate the influence of flaxseed-derived diglyceride-based high internal phase Pickering emulsions (HIPPE) at different levels (0%, 10%, 20%, 30%, 40%, and 50%) on the rheological and physicochemical properties of myofibrillar protein (MPs) gels. The study indicated that with increasing HIPPE levels, there was a significant increase in whiteness while a decrease in water-holding capacity. The gels with 10% HIPPE levels had higher ionic bonds, while those with 40% and 50% HIPPE levels showed higher hydrogen bonds. By increasing HIPPE levels in the formation of MP gels, the T2 relaxation time was found to decrease. Additionally, in all MP gels, G' values were significantly higher than G" values over time. Adding lower contents of HIPPE levels resulted in a more compact microstructure. These findings indicate that flaxseed-derived diglyceride-based HIPPEs could be utilized as fat substitutes in meat products to enhance their nutritional quality.

Impact of Flammulina velutipes polysaccharide on properties and structural changes of pork myofibrillar protein during the gel process in the absence or presence of oxidation

The present study aimed to investigate the impact of Flammulina velutipes polysaccharide (FVSP) on the rheological properties and structural alterations of myofibrillar protein (MP) and oxidized MP (OMP), utilizing techniques such as rhehometer, fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In the unoxidized system, the addition of 5.00% FVSP significantly improved (p < 0.05) the storage and loss moduli of the composite gel and promoted the α-helix to β-sheet transformation. These effects enhanced the protein's gel strength and water-holding capacity (WHC). In the oxidation system, 5.00% FVSP had significant effects (p < 0.05) on repair and improvement of the oxidized MP. These effects inhibited the cross-linking aggregation and degradation of the protein. In addition, the addition of FVSP significantly improved the gel properties of MPs after oxidation (p < 0.05), hindered fracture of the protein gel network structure. In summary, polysaccharides have a substantial effect on the functional characteristics of MP, and FVSP could potentially be applied in meat products.

Effect of vegetable oils on the thermal gel properties of PSE-like chicken breast meat protein isolate-based emulsion gels

To enhance the gel properties of PSE (pale, soft, and exudative)-like chicken meat protein isolate (PPI), the effect of peanut, corn, soybean, and sunflower oils on the gel properties of PPI emulsion gels was investigated. Vegetable oils improved emulsion stability and gel strength and enhanced viscosity and elasticity. The gel strength of the PPI-sunflower oil emulsion gel increased by 163.30 %. The thermal denaturation temperature and enthalpy values were increased. They decreased the particle size of PPI emulsion (P < 0.05) and changed the three-dimensional network structure of PPI emulsion gels from reticular to sheet with a smooth surface and pore-reduced lamellar. They elevated the content of immobile water PPI emulsion gels, decreased the α-helix and β-turn, and increased the β-sheet and random coil. Vegetable oil improved the gel properties of PPI in the following order: sunflower oil > soybean oil > corn oil ≈ peanut oil > control group.

Enhancement of the gelling properties of Aristichthys nobilis: Insights into intermolecular interactions between okra polysaccharide and myofibrillar protein

The effects of various contents of okra polysaccharide (OP) (0%-1%) on myofibrillar protein (MP) gelation and the interaction mechanism between OP and MP were investigated. OP improved the gelling properties of MP with an additive limitation of 0.75%. Rheological analysis demonstrated that the addition of OP enhanced the interactions between MPs, resulting in a denser intermolecular gel network structure. The addition of OP shifted the I850/I830 of Fourier transform infrared spectroscopy, indicating that hydrogen bonds were formed between OP and MP. Adding OP promoted the transition from α-helix to β-sheet in the MP. OP exposed the hydrophobic groups of MPs and increased the number of hydrophobic interactions between them, favoring the formation of a dense gel network. Molecular docking predicted that hydrogen bonds were the main force involved in the binding of OP and MP. Moderate OP promoted the aggregation of MPs and improved their functional properties, facilitating heat-induced gelation.

Effects of inulin with different polymerization degrees on the structural and gelation properties of potato protein

This study investigated the effect of inulin with different polymerization degrees (DP), including L-inulin (DP 2-6), M-inulin (DP 10-23) and H-inulin (DP 23-46), on the structural and gelation properties of potato protein isolate (PPI). Results revealed that textural properties (hardness, cohesiveness, springiness and chewiness) and water-holding capacity (WHC) of PPI-inulin composite gels were positively correlated with the inulin DP and addition content at 0-1.5% (w/v), but deteriorated at 2% due to phase separation. The addition of 1.5% H-inulin showed the most significant increment effects on the WHC (18.65%) and hardness (2.84 N) of PPI gel. Furthermore, M-/H-inulin were more effective in increasing the whiteness and surface hydrophobicity, as well as in strengthening hydrogen bonds and hydrophobic interactions than L-inulin. Fourier transform infrared spectroscopy analysis and microstructural observation indicated that inulin with higher DP promoted more generation of β-sheet structures, and leading to the formation of stronger and finer network structures.

Properties of co-gel between Tenebrio Molitor larvae protein and myofibrillar protein induced by transglutaminase

This study explored the effect of adding transglutaminase (TGase) to a co-gel of Tenebrio Molitor larvae protein (TMLP) and myofibrillar protein (MP). Different concentrations of TGase (0-90 U/g) were added to the co-gel. The results showed that 60 U/g TGase treatment significantly improved the gel strength and water holding capacity (WHC) by 26.51 g and 9.2 %, respectively. TGase promoted the rheological properties and accelerated the three-dimensional network structure of the co-gel. Moreover, TGase significantly increased (P < 0.05) the tyrosine residues, tryptophan residues content and hydrophobic interactions of the aliphatic groups. The chemical forces between the protein molecules changed. TGase promoted the transition of α-helix to β-sheet and free water to immobilized water, thereby improving the WHC of co-gel. The principal component analysis reflected the links among indicators. This study illustrated that TGase might be an effective strategy to improve the co-gel of TMLP and MP and emulsified meat products with insects.

Effect of apple high-methoxyl pectin on heat-induced gelation of silver carp myofibrillar protein

The effect of adding apple high-methoxy pectin (HMP) (0-3 mg∙mL-1) on heat-induced gel characteristics of low concentration silver carp myofibrillar protein (MP) (15 mg∙mL-1) was studied. It was found that the hardness of gel increased by 20.6 times with adding 2 mg∙mL-1 HMP. Besides, HMP aided in the development of disulfide bonds and the aggregation of hydrophobic groups. During gel formation, the maximal storage modulus (G') of samples supplemented with 2 mg·mL-1 HMP was raised by a factor of 2.7. Of note, the images of SEM showed that protein and water were tightly combined with a proper amount of HMP and made its pores more uniform and dense. Meantime, the addition of moderate amounts of HMP enabled the formation of gels with favorable texture and performance at low concentration of MP was identified, which could provide a theoretical reference for the design and production of flesh low-calorie food gel.

Study on the interaction and gel properties of pork myofibrillar protein with konjac polysaccharides

BACKGROUND

Natural myofibrillar protein (MP) is sensitive to changes in the microenvironment, such as pH and ionic strength, and therefore can adversely affect the final quality of meat products. The aim of this study was to modify natural MP as well as to improve its functional properties. Therefore, the quality improvement effect of konjac polysaccharides with different concentrations (0, 1.5, 3, 4.5 and 6 g kg-1 protein) on MP gels was investigated.

RESULTS

With a concentration of konjac polysaccharides of 6 g kg-1 protein, the composite gel obtained exhibited a significant improvement of water binding (water holding capacity increased by 7.71%) and textural performance (strength increased from 29.12 to 37.55 N mm, an increase of 8.43 N mm). Meanwhile, konjac polysaccharides could help to form more disulfide bonds and non-disulfide covalent bonds, which enhanced the crosslinking of MP and maintained the MP gel network structure. Then, with the preservation of α-helix structure (a significant increase of 8.11%), slower protein aggregation and formation of small aggregates, this supported the formation of a fine and homogeneous network structure and allowed a reduction in water mobility.

CONCLUSION

During the heating process, konjac polysaccharides could absorb the surrounding water and fill the gel system, which resulted in an increase in the water content of the gel network and enhanced the gel-forming ability of the gel. Meanwhile, konjac polysaccharides might inhibit irregular aggregation of proteins and promote the formation of small aggregates, which in turn form a homogeneous and continuous gel matrix by orderly arrangement. © 2023 Society of Chemical Industry.

Insight into the effect of large yellow croaker roe phospholipids on the physical properties of surimi gel and their interaction mechanism with myofibrillar protein

BACKGROUND

The present study aimed to investigate the effects of large yellow croaker roe phospholipids (LYCRPLs) on the physical properties of surimi gels and to clarify their interaction mechanism with myofibrillar proteins (MPs) in terms of chemical forces and the spatial conformation.

RESULTS

LYCRPLs could improve the gel strength, textural properties, rheological properties and water-holding capacity of surimi gels. Moreover, the interaction mechanism between LYCRPLs with MPs was revealed through intermolecular forces, Fourier transform infrared spectroscopy and ultraviolet visible absorption spectroscopy. The findings demonstrated that LYCRPLs enhanced the surface hydrophobicity and particle size of MPs, facilitating expansion and cross-linking of MPs.

CONCLUSION

These results provide a theoretical basis for improving the characteristics of surimi gels and thus facilitate the application of LYCRPLs in the aquatic food industry. © 2023 Society of Chemical Industry.

Excessive free radical grafting interferes with the macromolecular association and crystallization of brined porcine myofibrils during heat-set gelatinization

Free radical grafting and oxidative modification show superiority in myofibrillar protein (MP) aggregation patterns during salting process, but their consequent formation mechanisms of protein hydration network require further evaluation. Herein, we explored the effect of salt-curing (0, 1, 3 and 5 %) on MP protein polymer substrate, water-protein interaction, crystallization events and thermal stability under H2O2/ascorbate-based hydroxyl radical (•OH)-generating system (HRGS) (1, 10, 20 mM H2O2). Results showed that moderate salting (≤3%) favored the water binding of MP gels during the oxidation course. Accordingly, the maximum thermal stability (Tm) of MP gels was obtained at 3 % salting could be greatly attributed to the protein chain solubilization and refolding process. However, 5 % salt synergized with •OH oxidation intensified diffraction peak 2 (the most striking diffraction feature). Microstructural analysis validated a maximum compactness of MP gel following brining with 5 % salt at potent oxidation strength (20 mM H2O2). This study maybe promises efficient strategy to the myogenetic fibril products and biomaterials.

Chitin nanocrystals as natural gel modifier for yielding stronger acid-induced soy protein isolate gel

This study aimed to enhance the rheological properties and thermal stability of acid-induced soy protein isolate (SPI) gels by incorporating chitin nanocrystals (ChNCs) and proposing a gelation mechanism. SPI gels exhibited pseudo-plastic behavior. Increasing ChNCs concentration from 0.00 % to 1.00 % improved G' values, recovery rate, and initial degradation temperature: from 75.6 Pa to 1024.3 Pa, 80.27 % to 85.47 %, and 261.5 °C to 275.8 °C, respectively. FTIR analysis confirmed electrostatic and hydrogen bonding interactions between SPI and ChNCs. Adding 1.00 % ChNCs reduced α-helix content from 19.7 % to 12.1 % while increasing β-sheet content from 46.5 % to 52.6 %. This led to protein unfolding, exposure of Trp residues, and orderly aggregation, forming a dense cross-linked gel network. Gel particle size increased from 185.5 nm (no ChNCs) to 504.4 nm (1.00 % ChNCs), with reduced surface charges. Hydrophobic and electrostatic interactions were key forces stabilizing SPI-ChNCs gels. These findings offer a practical approach to enhancing traditional acid-induced protein gel-based functional foods using naturally sourced chitin nanocrystals.

Effects of limited enzymatic hydrolysis and polysaccharide addition on the physicochemical properties of emulsions stabilized with duck myofibrillar protein under low-salt conditions

This study aimed to investigate the role of hydrolysis and guar gum (GG) participation on the emulsification of the duck myofibrillar protein (MP) and the related stability of oil-in-water emulsion in low-salt condition. Emulsions were prepared using one of each or both treatments, and that prepared with trypsin hydrolysis and GG (T-GG) exhibited the highest stability. FTIR analysis confirmed the hydrogen bond interactions between the system components. T-GG treatment improved emulsion properties and decreased oil droplet size. Moreover, CLSM indicated that aggregation of T-GG oil droplets was prevented. Physical stability was assessed such as Turbiscan stability index, creaming index, and rheological properties. The adsorbed percentage for T-GG was the lowest. However, interfacial tension, droplet size, stability, and peroxide value analyses indicated that a denser interfacial membrane structure is formed with T-GG. Thus, T-GG treatment could be applied in the food industry, such as in nutrient delivery systems and fat mimetics.

Ameliorating the stability of native/thermally denatured chicken-derived myofibrillar proteins particles in an aqueous system: The synergistic effect of acidification combined with inulin and inulin/sodium alginate

The effect of acidification through hydrochloric acid combined with inulin (In), and inulin/sodium alginate (In/SA) on the stability of native/thermally denatured myofibrillar proteins (MPs/TMPs) particles in an aqueous system was investigated. At the same pH, MPs-In and TMPs-In particles were smaller and had higher absolute potentials than MPs-In/SA and TMPs-In/SA particles. Additionally, the size of MPs-In particles reached 1 μm, and the solubility increased from 21.73 ± 0.57 % to 76.26 ± 1.27 % when the pH was reduced from 5.0 to 3.0. The absolute potential of TMPs 3-In particles increased from 15.77 ± 0.72 to 28.20 ± 0.30 mV, and the solubility increased from 18.65 ± 0.72 % to 74.53 ± 0.74 %. Confocal laser microscopy revealed that, compared with pH 5.0 or 4.0, MPs-In/TMPs-In particles dispersed more evenly at pH 3.0 compared with pH 5.0 or 4.0. This further confirmed that electrostatic repulsion between particles maximally contributed to particle stability. Furthermore, the α-helix content in TMPs-In particles at pH 3.0 decreased from 41.51 ± 1.09 % (TMPs control) to 16.61 ± 1.87 %. This decrement of an up to 60 % led to decreased intramolecular hydrogen bonds and improved surface hydrophobicity. Therefore, a single polysaccharide (In) combined with MPs/TMPs particles exhibited higher dispersion and stability at pH 3.0. These findings could provide new insights into chicken-derived protein beverage processing.

Effects of blackberry (Rubus spp.) polysaccharide on the structure and thermal behavior of the myofibrillar protein of chicken breast meat

Blackberry crude polysaccharides (BCP) was added to chicken breast to inspect the intermolecular interaction with myofibrillar protein (MP). The influence of BCP on the thermal transformation behavior and protein micro-structure during temperature rise period was studied. The results showed that the interaction between BCP and MP was mainly affected by the concentration of BCP and heating temperature. The results of infrared spectrophotometer and nano-particle/zeta potentiometer showed that a BCP-MP complex was generated through hydrogen bond and electrostatic interaction, which could promote the transformation of MP from β-folding to β-Angle transformation. The fluorescence spectra showed that the BCP was helped to the spread of protein structure of the MP. Moreover, synchronous thermal analyzer and rheometer results revealed that the BCP increased the enthalpy value and elastic modulus of MP. Scanning electron microscope verified pores inside the BCP-MP complex are more evenly distributed and smaller, which led to the high cross-linking of network and good stability of water distribution for the MP. The addition of BCP enhances the hydrogen bonds and disulfide bonds of MP molecules, which can strengthen the network structure and ultimately improve the performance of meat products.

Using nanocellulose to improve heat-induced cull cow meat myofibrillar protein gels: effects of particle morphology and content

BACKGROUND

Enhancing protein gel properties is essential to improve the texture of meat products. In this study, the improvement effects of three types of nanocellulose, i.e. rod-like cellulose nanocrystals (CNC), long-chain cellulose nanofibers (CNF) and spherical cellulose nanospheres (CNS) with different concentrations (1, 3, 5, 10, 15 and 20 g kg-1 ), on cull cow meat myofibrillar protein (MP) gel were investigated.

RESULTS

Compared with needle-shaped CNC and spherical CNS, the addition of 10 and 20 g kg-1 long-chain CNF had the most significant improvement effect on gel hardness and water-holding capacity, respectively (P < 0.05), increasing to 160.1 g and 97.8%, respectively. In addition, the incorporation of long-chain CNF shortened the T2 relaxation time and induced the formation of the densest network structure and promoted the phase transition of the gel. However, excessive filling of nanocellulose would destroy the structure of the gel, which was not conducive to the improvement of gel properties. Fourier transform infrared results showed that there was no chemical reaction between the three nanocellulose types and MP, but the addition of nanocellulose was conducive to gel formation.

CONCLUSION

The improvement of MP gel properties by adding nanocellulose mainly depends on its morphology and concentration. Nanocellulose with higher aspect ratio is more beneficial to the improvement of gel properties. For each nanocellulose type, there is an optimal addition amount for MP gel improvement. © 2023 Society of Chemical Industry.

Mechanism on the Synergistic Gelation of the Myofibrillar Protein Composite Gel Enhanced by "Clean-Label" Skin Functional Protein Powders

The concept of healthiness and sustainability has promoted the innovation and development of "clean-label" products. Herein, this study aims to explore the influence mechanism of "clean label" skin protein powder (FPP) on the gelation properties of myofibrillar proteins (MPs). Specifically, the addition of FPP (0.2-4.0%) can improve the water holding capability and texture properties of MP composite gels. When the FPP concentration is over 1.0%, the composite gels exhibit no significant water loss during centrifugation. Dynamic rheology and sodium-dodecyl sulfate-polyacrylamide gel electrophoresis results revealed that FPP can slow the aggregation and denaturation of myosin and promote the formation of disulfide bonds between myofibril proteins, thus forming a stable network structure. Structural observation revealed that FPP can fill into the MP gel and lead to the formation of compact gel structures. Besides, with the increase of FPP concentration, the chemical forces involved in structural stabilization change significantly. Specifically, hydrophobic interaction and hydrogen bonding are the dominant forces at a lower FPP concentration (0.2 and 0.4%), while the ionic bond and disulfide bond are the dominant forces at a higher concentration. Overall, this work demonstrated that FPP can significantly improve the gel functionality of MP by altering the gel structure and strengthening the molecular forces.

Impacts of Industrial Modification on the Structure and Gel Features of Soy Protein Isolate and its Composite Gel with Myofibrillar Protein

Native soy protein isolate (N-SPI) has a low denaturation point and low solubility, limiting its industrial application. The influence of different industrial modification methods (heat (H), alkaline (A), glycosylation (G), and oxidation (O)) on the structure of SPI, the properties of the gel, and the gel properties of soy protein isolate (SPI) in myofibril protein (MP) was evaluated. The study found that four industrial modifications did not influence the subunit composition of SPI. However, the four industrial modifications altered SPI's secondary structure and disulfide bond conformation content. A-SPI exhibits the highest surface hydrophobicity and I_850/830 ratio but the lowest thermal stability. G-SPI exhibits the highest disulfide bond content and the best gel properties. Compared with MP gel, the addition of H-SPI, A-SPI, G-SPI, and O-SPI components significantly improved the properties of the gel. Additionally, MP-ASPI gel exhibits the best properties and microstructure. Overall, the four industrial modification effects may impact SPI's structure and gel properties in different ways. A-SPI could be a potential functionality-enhanced soy protein ingredient in comminuted meat products. The present study results will provide a theoretical basis for the industrialized production of SPI.

Synergistic effects of oat β-glucan combined with ultrasound treatment on gel properties of silver carp surimi

The effect of oat β-glucan (OG) combined with ultrasound treatment on the gelation properties of silver carp surimi with different salt contents was investigated. The results demonstrated that the gelation properties of surimi gels at high salt concentration were superior than those at low salt level. The addition of OG or ultrasound treatment could significantly enhance the texture properties, gel strength and water holding capacity (WHC) of gel samples, regardless of salt contents. The ultrasound treatment improved the whiteness of surimi gels, whereas the OG addition slightly declined the whiteness. Both OG addition and ultrasound treatment markedly reduced the total sulfhydryl content (total SH) and strengthened the hydrophobic interactions, forming the more uniform and denser gel network structures, hence more water was captured in network structures and became immobilized. Moreover, the combined treatment of OG and ultrasound showed synergic action on the gelation properties of surimi, and the gel strength and WHC of low-salt surimi gel treated by the combination of OG and ultrasound were even superior than that of high-salt gel without OG by traditional heating.

Quinoa protein Pickering emulsion: A promising cryoprotectant to enhance the freeze-thaw stability of fish myofibril gels

In this work, the effects of different QPE addition on the freeze-thaw (F-T) stability of fish myofibrillar protein (MP) gels were revealed. During freezing process, QPE decreased the freezing point of MP gels and shortened the time to pass through the maximum-ice-crystal-formation zone. The occurrence of thermal hysteresis effect led to the formation of small ice crystals and alleviated the damage to MP gel network. The incorporation of 7.5% QPE also reduced the free water amount to 19.23% and improved the water holding capacity of MP gels. Furthermore, the incorporation of QPE decreased the carbonyl content of MP gels after F-T cycles and delayed the protein oxidation. Meanwhile, QPE addition maintained the stability of the tertiary structure of MP gels via stabilizing the microenvironment of tyrosine and tryptophan. Overall, QPE shows the potential as a new cryoprotectant to improve the F-T stability of MP gel products.

Effects of combined chickpea protein isolate and chitosan on the improvement of technological quality in phosphate-free pork meat emulsions: Its relation to modifications on protein thermal and structural properties

The effects of combined chickpea protein isolate (CPI, 1%, w/w) and chitosan (CHI, 1%, w/w) on the technological, thermal, and structural properties of phosphate-free pork meat emulsions (PPMEs) were investigated. The results showed that CPI + CHI significantly improved the emulsion stability (P < 0.05), synergistically elevated the hardness and chewiness, and did not negatively impact the color attributes, which endowed the PPMEs with similar or even better technological performances compared to the high-phosphate control. These alterations were related to the reduced myosin enthalpy values, the rearrangement of free water into immobilized water, the synergistic reduction in α-helical structure and increase in β-sheet structure, the increased trans-gauche-trans SS conformation intensity of the Raman bands, and the formation of interactive protein gel networks where small-sized fat particles were evenly dispersed in the protein matrix. Therefore, combined CPI and CHI shows promise as a phosphate replacer for meat products.

In-Depth Insight into the Mechanism of Incorporation of Abelmoschus manihot Gum on the Enhancement of Gel Properties and In Vitro Digestibility of Frankfurters

This study aimed to investigate the effects of different concentrations (0.1, 0.2, 0.3, 0.4, and 0.5% w/w) of Abelmoschus manihot gum (AMG) on the gel properties and in vitro digestibility of frankfurters. The results indicated that AMG incorporation significantly enhanced the emulsion stability and texture of frankfurters, as well as the dynamic rheological characteristics of raw meat batter, with the optimal concentration being 0.3% (p < 0.05). Furthermore, hydrogen bonds and disulphide bonds were the main molecular forces of the frankfurters in the presence of AMG. Microstructural images showed that more uniform and dense microstructures of frankfurters were formed due to AMG supplementation. In addition, AMG incorporation significantly increased the in vitro protein digestibility of frankfurters as the level of addition increased (p < 0.05). In conclusion, our results provided critical information for the practical application of AMG in the production of emulsified meat products.

Blue agave inulin-soluble dietary fiber: effect on technological quality properties of pangasius mince emulsion-type sausage

BACKGROUND

The aim of the work was to investigate the influence of supplementing pangasius mince-based emulsion sausages with blue agave-derived inulin at 1% (T1), 2% (T2), 3% (T3), 4% (T4), and 5% (T5) on its technological quality attributes and acceptability.

RESULTS

The cooking yield of T-2, T-3, and T-4 sausages (96-97%) exhibited no significant difference (P > 0.05), which was higher than the other lots. The T-2 batter exhibited a significant difference with all other treatments, showing the lowest total expressible fluid (12.20%) value, indicating the highest emulsion stability of the batter. There was a significant effect on the diameter reduction of the cooked sausages as the level of inulin increased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed the proteolysis of raw mince without inulin and new bands in cooked sausage samples were observed. Increasing inulin content increased the hardness of the sausages from 2510.81 ± 114.31 g to 3415.54 ± 75.88. The differential scanning calorimetry melting temperatures of peak 2 of the T-1, T-2, T-3, and T-4 increased as the inulin content increased from 1 to 4%. The scanning electron microscope images exhibited a smooth appearance on the surface as the inulin level increased.

CONCLUSION

The sausages incorporated with the 2% and 3% blue agave plant-derived inulin (T-2 and T-3) showed better sensory overall acceptability scores than the control. The results suggested that the blue agave plant-derived inulin could be efficiently utilized at the 2% and 3% levels to enhance the quality of emulsion-type pangasius sausage. © 2023 Society of Chemical Industry.

Inulin for surimi gel fortification: Performance and molecular weight-dependent effects

Inulin is a prebiotic carbohydrate widely used in food industry due to its health benefits and unique rheological properties. For the first time, this study explores the potential of natural inulin as a sustainable food additive to enhance surimi gel characteristics, specifically focusing on understanding its molecular weight effects. The good solubility of inulin facilitates the conversion of α-helix to other secondary conformations which are favorable for protein denaturation and aggregation during gelation. Moreover, the abundant -OH groups at the surface of inulin can boost the chemical forces within surimi proteins to reinforce the gel network. Compared to short-chain inulin, long-chain inulin can alleviate proteolysis, enhance hydrophobic interactions and intertwine with myosin molecules, thereby reinforcing the gel network. A more viscous long-chain inulin solution formed within surimi gels fills the space between aggregated proteins and facilitates the lock of water molecules, improving the water-holding capacity (WHC). Thus, an addition of 12 % long-chain inulin leads to an enhanced hardness of surimi gel from 943 to 1593 and improved WHC from 72 % to 85 %. A new inulin-myosin interaction mechanism model is also proposed to provide useful guidelines for surimi processing and expanding the application of inulin within the food industries.

Effects of conjugates of ε-polylysine-dextran created through Maillard reaction on quality and storage stability of the chicken gel

The present study mainly focused on the effects of the conjugates of PL-dextran produced through the Maillard reaction on the quality and storage stability of chicken gel for 5 days at 4 ℃. According to the results of the texture profile, water retention capacity (WRC), low-field nuclear magnetic resonance (LF NMR), aerobic plate count (APC), and total volatile basic nitrogen (TVBN), ε-polylysine (PL) could improve chicken gel storage stability while decreasing the quality of protein gels (p < 0.05). Additionally, adding dextran with high or low molecular weight could significantly increase the quality of gel during storage (p < 0.05), whereas decreased storage stability could be obtained (p < 0.05). In general, conjugates formed by PL and dextran with high molecular weight were beneficial for quality maintenance. In comparison, the polymers produced from the low molecular weight of dextran could modify the storage stability of gels. Adding conjugates of dextran and PL benefited the structure formation of protein gel, while PL would retain part of antibacterial activity when crosslinked with dextran. Therefore, it could be concluded that the quality improvement effect of PL-dextran addition on gel quality was greater than its antibacterial effect, which would impact the formulation design of novel emulsion-type meat products.